This invention relates to a crop harvesting header including a cutter bar and a reel for controlling movement of the crop in the area over the cutter bar. The reel is rotatable about an axis generally parallel to the cutter bar and has a plurality of reel bats each having reel fingers projecting generally radially outwardly from the reel axis. The reel bats are pivotal each about a respective bat axis parallel to the reel axis so as to vary the angle of the fingers about the bat axis as the reel rotates. The reel co-operates with a cam carried on the header in generally stationary position so that each bat has a crank arm with a cam follower on the crank arm which follows the cam as the reel rotates and causes the required pivotal movement of the bat.
Attention is directed to co-pending Application Serial No. 60/325,544 filed on the same filing date (Remillard) assigned to the same assignees which discloses a header using the same invention as set forth herein, the disclosure of which is incorporated herein by reference.
Some headers of the above type include a reel which has the reel axis fixed relative to the header and particularly the cutter bar. Many of these headers include a cam which is fixed on the end frame of the header and is shaped in a complex non-circular pattern so that the fingers follow a complex non-cylindrical path.
Other headers of this type include a reel which is mounted on reel arms which can raise and lower the reel relative to the cutter bar to provide different conditions for different crops.
In U.S. Pat. No. 4,751,809 (Fox et al) assigned to the present applicant is disclosed an arrangement in which the movement of the bats is controlled by a rotating ring carried by the reel on the same reel arms but rotating about an axis off-set from the reel axis.
In U.S. Pat. No. 6,170,244 (Coers et al) assigned to Deere and Company and in Canadian Application 2289164 also by the same inventor is disclosed an arrangement in which the reel is mounted on reel arms and there is provided a cam which is carried also on the reel arms so that it raises and lowers with the reel but it is held at a position so that it does not rotate with the reel and controls the angle of the bats by crank arms and cam followers travelling on the cam.
The present invention is concerned with headers including a reel both of the type in which the reel is fixed relative to the cutter bar and of the type in which the reel is mounted on arms which allow the reel to raise and lower relative to the cutter bar.
Pickup reels which use a cam path to establish desired finger angles relative to the cutting device are used on forage and crop harvesting equipment. Conventional designs use a rotating reel with one or more transversely mounted sets of fingers mounted at fixed radius to the reel center. Each set of fingers, on a bat, also has the ability to rock about its own axis of rotation that is parallel to the reel axis. A crank arm with a cam follower is fixed rigidly to each set of reel fingers. The cam follower follows a cam path that is shaped to change finger angle as the reel rotates.
It is one object of the present invention to provide a header which includes an improved drive to the bat fingers.
According to a first aspect of the invention there is provided a crop harvesting header comprising:
a header frame structure arranged for movement in a direction of working movement across ground carrying a crop to be harvested;
a cutter bar arranged across a forward edge of the header frame structure for cutting the crop;
a cut crop transport arrangement mounted on the header frame structure for receiving and transporting the cut crop for further processing;
and a reel for controlling movement of the crop in the area over the cutter bar;
the reel being mounted on the header frame structure for movement therewith in the direction of movement and for rotation about a reel axis generally parallel to the cutter bar;
the reel having a plurality of reel bats at spaced positions around the reel axis each having reel fingers projecting generally radially outwardly from the reel axis;
each of the reel bats being pivotal about a respective bat axis parallel to the reel axis so as to vary the angle of the fingers about the bat axis as the reel rotates;
a stationary cam mounted on the header frame structure at the reel in stationary position relative to the reel axis;
each bat having associated therewith a crank arm with a cam follower on the crank arm which follows the cam as the reel rotates such that the movement of the follower in the cam as the reel rotates relative to the cam causes the crank arm to move relative to the bat axis to generate the required pivotal movement of the bat;
wherein, for each of the bats, the cam follower is arranged in the cam at a position which is angularly advanced about the reel axis relative to the bat axis.
The header frame structure may include reel arms which support the reel and cam for up and down movement relative to the cutter bar or more preferably the reel may be directly mounted on end frame elements fixed relative to the cutter bar.
The term xe2x80x9cbatxe2x80x9d used herein is not intended to imply any particular shape or construction of the bat and this may comprise merely a tube, sometimes known as a tine tube, or other longitudinal structural member which carries the bat fingers so as to project radially outwardly from a longitudinal bat axis of the bat.
Preferably, for each bat, the respective crank arm has an end thereof opposite the cam follower directly connected to the bat at a fixed angle relative thereto. However other arrangements of the crank arm can be used including intervening links between the crank arm and the bat, for example of the type shown in the above mentioned copending application.
The fixed angle between the crank arm and the bat fingers while fixed during use may be adjustable to obtain different finger action.
In this arrangement, the opposite end of the crank arm is preferably fixed to the bat so as to rotate about the bat axis.
In this arrangement, the angle between the crank arm and the bat fingers is greater than 90 degrees, more preferably in the range 110 to 160 degrees and most preferably of the order of 135 degrees.
Preferably the cam is arranged such that the path length in a bottom half is less than a path length in an upper half.
Preferably the cam is arranged such that the cam lies radially inwardly of the path of the bat axes in a bottom part of the cam and lies radially outwardly of the path of the bat axes in an upper part of the cam.
Preferably the cam is arranged such that the path length thereof per degree of rotation of the reel is shorter in the angles of movement of the reel where the fingers are in engagement with the crop than at other angles.
Preferably the length of the crank arm from the bat axis to an axis of the cam follower is at least 3.0 inches and preferably of the order of 5.0 inches.
Preferably the reel is arranged such that the bat fingers at bottom dead center of the reel relative to the reel axis are in front of the cutter bar, such that the bat fingers follow a finger pattern in which the bat fingers are angularly advanced about the respective bat axis to the greatest extent at a position in front of bottom dead center, are generally radial at the bottom dead center and are angularly retarded to the greatest extent at a position behind and upwardly of the cutter bar.
The improved arrangement defined above may result in greater clearance to crop entry, improved mechanical advantages, improved range of motion and improved cam durability.
The major difference with the new invention is that the finger to crank arm angle is set so that the crank pushes the follower through the cam path rather than pulling the follower through the cam track as in conventional designs.